WIRING
PRECAUTIONS
• Connect the AC power supply to the dedicated terminals
specified in this manual.
If an AC power supply is connected to a DC input/output
terminal or DC power supply terminal, the PLC will burn out.
• Do not wire vacant terminals externally.
Doing so may damage the product.
• Use class D grounding (grounding resistance of 100Ω or less)
with a wire of 2mm2 or thicker on the grounding terminal of the
FX3U Series main unit.
However, do not connect the ground terminal at the same point
as a heavy electrical system.
• When drilling screw holes or wiring, make sure cutting or wire
debris does not enter the ventilation slits.
Failure to do so may cause fire, equipment failures or
malfunctions.